new, sterile ones. The scheme is aimed
at reducing the risks of infections, such
as HIVand hepatitis, transmitted by the
sharing of contaminated needles.
needlestick injuryAccidental puncture
of the skin by a contaminated hypoder-
mic needle. Hospital staff are most likely
to be at risk. Needlestick injuries carry
the risk of serious infections, such as
HIVand hepatitis, and need immediate
attention. The wound should be cleaned
thoroughly; blood tests may be needed
to determine whether infection has
been transmitted.
nefopamAn analgesic drugused to
relieve moderate pain caused, for exam-
ple, by injury, surgery, or cancer. Possible
adverse effects include nausea, nervous-
ness, dry mouth, and difficulty sleeping.
Nelson’s syndromeA rare disorder of
the endocrine system that causes
increased skin pigmentation. Nelson’s
syndrome results from enlargement of
the pituitary gland, which can follow
removal of the adrenal glands(a treat-
ment for Cushing’s syndrome).
Nelson’s syndrome is treated by
hypophysectomy(removal or destruc-
tion of the pituitary gland).
nematodesThe scientific name for a
group of cylindrically shaped worms
(roundworms), some of which can be
parasites of humans.
neologismThe act of making up new
words that have a special meaning for
the inventor. The term also refers to the
invented words themselves. Persistent
neologism can be a feature of speech in
people with schizophrenia.
neomycinAn antibiotic drugused in the
treatment of ear, eye, and skin infections,
often in combination with other drugs.
Neomycin is sometimes given to pre-
vent infection of the intestine prior to
surgery. Possible adverse effects include
rash and itching.
neonateA newly born infant, under the
age of 1 month (see newborn).
neonatologyThe branch of paediatrics
concerned with the care of newborn
infants and the treatment of disorders
during the first few weeks of life.
neoplasiaA medical term for tumour
formation. The term neoplasia does not
necessarily imply that the new growth iscancerous; neoplasia also results in
tumours that are noncancerous.
neoplasmA medical term for a tumour
(any new abnormal growth). Neoplasms
may be cancerousor noncancerous.
neostigmineA drug that is used to treat
myasthenia gravis(a rare autoimmune
disorder that causes muscle weakness).
Neostigmine increases the activity of
acetylcholine, a neurotransmitterthat
stimulates the contraction of muscles.
Possible adverse effects of neostigmine
include nauseaand vomiting, increased
salivation, abdominal cramps, diarrhoea,
blurred vision,muscle cramps, sweating,
and twitching.
nephrectomySurgical removal of 1 or
both of the kidneys.
One of the most common reasons for
nephrectomy is to remove a cancerous
tumour (see kidney cancer). A kidney may
also be removed if it is not functioning
normally due to injury, infection, or the
presence of stones (see calculus, urinary
tract), or if it is causing severe hyperten-
sion(high blood pressure).
On removal of a single kidney the re-
maining kidney takes over the workload.
If both kidneys are removed, the patient
requires dialysisor a kidney transplant.
nephritisInflammation of 1 or both kid-
neys. Nephritis may be caused by an
infection (see pyelonephritis), abnormal
responses of the immune system(see
glomerulonephritis), or metabolic disor-
ders, such as gout.
nephroblastomaSee kidney cancer.
nephrocalcinosisDeposits of calcium
within the tissue of 1 or both kidneys.
Nephrocalcinosis is not the same as
kidney stones (see calculus, urinary tract),
in which calcium particles develop in-
side the drainage channels of the kidney.
Nephrocalcinosis may occur in any
condition in which the level of calcium
in the blood is raised. It may also occur
as a result of taking excessive amounts
of certain antacid drugsor vitamin D.
Treatment is of the underlying cause to
prevent further calcification.
nephrolithotomyThe surgical removal
of a calculus(stone) from the kidney.
Nephrolithotomy may be performed
through an abdominal incision, or via
a puncture incision in the back. LargeNEEDLESTICK INJURY NEPHROLITHOTOMYN